1. Field of the Invention
The present invention relates to a water purifying apparatus provided with an under-sink type water purifier, and more particularly to one capable of delaying bacterial development in tap water confined in a container of the water purifier thereof in use.
2. Description of the Prior Art
Heretofore, in order to eliminate residual chlorine (which is used for disinfecting) and odor materials from tap water, it has been known to use a water purifying apparatus in home kitchens and restaurants. The water purifying apparatus employs a water purifier provided with a water-flow type container in which suitable absorbents such as activated charcoal and the like are contained. The container of the water purifier has a water-inlet and a water-outlet port which are connected with a water-supply pipe and a water-discharge pipe, respectively. Further, in some cases, the water purifier has additional filters such as microporous filters or ultrafilters for removing bacteria from tap water. The water purifying apparatus, which has its water-inlet port connected with a tap-water distributing pipe, eliminates residual chlorine and odor materials dissolved in tap water, and discharges a purified water from its water-outlet port.
Of these water purifying apparatuses, some apparatuses have their water purifier mounted in cabinets under sinks of kitchens. Each of these so-called under-sink type water purifier has its water-tap portion only disposed above the sink, the water-tap portion being connected with a main body of the water purifier through pipes to enable the water-tap portion to permit and prevent alternately the discharge of the purified water therefrom. Starting-stopping of discharge of the purified water from the water-tap portion is directly controlled by operating a handle of the water tap, or remotely controlled by the use of a suitable remote control means. Incidentally, since the users of today prefer high-grade products, it increases the tendency of the water-tap portion to be remotely controlled.
In the above remote-control means, a contactless type object sensor (which utilizes infrared rays, ultrasonic waves or like waves for detecting an object) is provided in the water-tap portion of the water purifying apparatus. In operation, only when the object, for example such as a user's hand is near the object sensor, the sensor issues a detection signal for permitting the water-tap portion to discharge the purified water therefrom. More particularly, the detection signal issued from the object sensor is transmitted to a solenoid valve (which is disposed under the sink) to cause the valve to be opened, so that the purified water passes through the valve and is discharged from the water-tap portion of the water purifier.
As for the object sensor of the remote-control means, there are two types of the sensors. One is a set/reset type, and the other is a reaction type. In the water purifier provided with the set/reset type object sensor, the water-tap portion alternately starts and stops the discharge of the purified water therefrom each time the user's hand is near the sensor. On the other hand, in the water purifier provided with the reaction type object sensor, the water-tap portion continuously discharges the purified water as long as the user's hand is near the sensor.
Further, in the water purifier provided with the set/reset type object sensor, a sensible area of the sensor is not formed in front of the sink, but formed in an area adjacent to a right or a left side of the sink so as to prevent the sensor from issuing a signal when other objects such as a cup and the like is near the sensor. On the other hand, in the water purifier provided with the reaction type object sensor, a sensible area thereof is formed in front of the sink to permit the water-tap portion to discharge the purified water only when the object such as the user's hand the like is near the sensor.
Further, in the water purifying apparatus, in place of the above contactless type object sensor, it is possible to use a push-button type mechanical switch which issues a detection signal when the user pushes a push button of the switch.
In addition, in the water purifying apparatus, in place of the object sensor mounted on the water tap, it is possible to mount a mechanical foot-operated switch in the vicinity of a floor near the kitchen cabinet.
The use of the above mechanical push-button type and the mechanical foot-operated switch is well known.
However, in any type of these conventional water purifying apparatus, there is a fear that bacterial development is enhanced in the tap water (which is confined in the container of the water purifier) to such an extent that the confined water can not be used as a drinking water when the purifier is not used for a long period of time, because the residual chlorine (which is used for disinfecting and dissolved in the confined water) is substantially completely absorbed in the absorbents of the purifier.